The reinforcement of resins with glass fibers is known in the art. By way of illustration, the following patents disclose the reinforcement of resinous materials with glass fibers using polyester resins and organosilicon compounds as adhesion promoters:
(1) U.S. Pat. No. 3,728,146 which discloses the reinforcement of elastomeric materials with glass fibers by a method which comprises impregnating a glass fiber bundle with an elastomer or resinous polymer and then coating the glass fiber bundle with an elastomer compatible material. Disclosure is made in the patent of polyester resin as a useful impregnating material and of organosilicon compounds as elastomer compatible materials.
(2) U.S. Pat. No. 2,931,739 which discloses the reinforcement of resinous materials with glass fibers using an organosilicon compound combined with a polyester resin as an adhesion promoter. While a saturated polyester is disclosed as a preferred embodiment in that patent, mention is made of unsaturated polyester resins (see column 4, lines 74-75; column 5, lines 1-16; and Example 8 of the patent).
(3) U.S. Pat. No. 3,252,825 which discloses a process for coating glass fibers with the hydrolyzed condensation product of amino silane and a polymer or polymerforming material. Specific mention is made in the patent of the reaction of an unsaturated polyester with alphaaminopropyltriethoxysilane to form an aqueous size (see Example 4, column 6, of the patent).
(4) U.S. Pat. No. 3,658,571 which discloses a method of reinforcing elastomeric materials with glass fibers using a composition which may contain polyester resins and which may contain an organosilicon compound.
In addition, other prior art references disclose the reaction of unsaturated polyester with halosilanes to produce silylated polyesters. For example, a publication (43 Paint Research Institute Proceedings 558, 49-53, (1974)) discloses the reaction of alkyl and aryl-dichlorosilanes with unsaturated polyesters to produce chlorosilane-containing polyesters. The chlorosilane-containing polyesters are then reacted with water to produce silane diols. Another publication (Polymer Letters Edition 11, 327-332, (1973)) discloses the hydrosilation of unsaturated polyesters with dichloromethylsilane to produce silane diols.
It is desirable to produce polyester silane adhesion promoters having improved properties by the Michael addition reaction of an unsaturated conjugated polyester with an aminoalkylalkoxysilane. It is also desirable to produce a polyester silane adhesion promoter that is suitable for the reinforcement of organic resins with any inorganic siliceous material, including glass fibers and glass cloth.